Index: gfx/codec/jpeg_codec.cc |
=================================================================== |
--- gfx/codec/jpeg_codec.cc (revision 73487) |
+++ gfx/codec/jpeg_codec.cc (working copy) |
@@ -1,535 +0,0 @@ |
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "gfx/codec/jpeg_codec.h" |
- |
-#include <setjmp.h> |
- |
-#include "base/logging.h" |
-#include "base/scoped_ptr.h" |
-#include "third_party/skia/include/core/SkBitmap.h" |
-#include "third_party/skia/include/core/SkColorPriv.h" |
- |
-extern "C" { |
-#if defined(USE_SYSTEM_LIBJPEG) |
-#include <jpeglib.h> |
-#else |
-#include "jpeglib.h" |
-#endif |
-} |
- |
-namespace gfx { |
- |
-// Encoder/decoder shared stuff ------------------------------------------------ |
- |
-namespace { |
- |
-// used to pass error info through the JPEG library |
-struct CoderErrorMgr { |
- jpeg_error_mgr pub; |
- jmp_buf setjmp_buffer; |
-}; |
- |
-void ErrorExit(jpeg_common_struct* cinfo) { |
- CoderErrorMgr *err = reinterpret_cast<CoderErrorMgr*>(cinfo->err); |
- |
- // Return control to the setjmp point. |
- longjmp(err->setjmp_buffer, false); |
-} |
- |
-} // namespace |
- |
-// Encoder --------------------------------------------------------------------- |
-// |
-// This code is based on nsJPEGEncoder from Mozilla. |
-// Copyright 2005 Google Inc. (Brett Wilson, contributor) |
- |
-namespace { |
- |
-// Initial size for the output buffer in the JpegEncoderState below. |
-static const int initial_output_buffer_size = 8192; |
- |
-struct JpegEncoderState { |
- explicit JpegEncoderState(std::vector<unsigned char>* o) |
- : out(o), |
- image_buffer_used(0) { |
- } |
- |
- // Output buffer, of which 'image_buffer_used' bytes are actually used (this |
- // will often be less than the actual size of the vector because we size it |
- // so that libjpeg can write directly into it. |
- std::vector<unsigned char>* out; |
- |
- // Number of bytes in the 'out' buffer that are actually used (see above). |
- size_t image_buffer_used; |
-}; |
- |
-// Initializes the JpegEncoderState for encoding, and tells libjpeg about where |
-// the output buffer is. |
-// |
-// From the JPEG library: |
-// "Initialize destination. This is called by jpeg_start_compress() before |
-// any data is actually written. It must initialize next_output_byte and |
-// free_in_buffer. free_in_buffer must be initialized to a positive value." |
-void InitDestination(jpeg_compress_struct* cinfo) { |
- JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data); |
- DCHECK(state->image_buffer_used == 0) << "initializing after use"; |
- |
- state->out->resize(initial_output_buffer_size); |
- state->image_buffer_used = 0; |
- |
- cinfo->dest->next_output_byte = &(*state->out)[0]; |
- cinfo->dest->free_in_buffer = initial_output_buffer_size; |
-} |
- |
-// Resize the buffer that we give to libjpeg and update our and its state. |
-// |
-// From the JPEG library: |
-// "Callback used by libjpeg whenever the buffer has filled (free_in_buffer |
-// reaches zero). In typical applications, it should write out the *entire* |
-// buffer (use the saved start address and buffer length; ignore the current |
-// state of next_output_byte and free_in_buffer). Then reset the pointer & |
-// count to the start of the buffer, and return TRUE indicating that the |
-// buffer has been dumped. free_in_buffer must be set to a positive value |
-// when TRUE is returned. A FALSE return should only be used when I/O |
-// suspension is desired (this operating mode is discussed in the next |
-// section)." |
-boolean EmptyOutputBuffer(jpeg_compress_struct* cinfo) { |
- JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data); |
- |
- // note the new size, the buffer is full |
- state->image_buffer_used = state->out->size(); |
- |
- // expand buffer, just double size each time |
- state->out->resize(state->out->size() * 2); |
- |
- // tell libjpeg where to write the next data |
- cinfo->dest->next_output_byte = &(*state->out)[state->image_buffer_used]; |
- cinfo->dest->free_in_buffer = state->out->size() - state->image_buffer_used; |
- return 1; |
-} |
- |
-// Cleans up the JpegEncoderState to prepare for returning in the final form. |
-// |
-// From the JPEG library: |
-// "Terminate destination --- called by jpeg_finish_compress() after all data |
-// has been written. In most applications, this must flush any data |
-// remaining in the buffer. Use either next_output_byte or free_in_buffer to |
-// determine how much data is in the buffer." |
-void TermDestination(jpeg_compress_struct* cinfo) { |
- JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data); |
- DCHECK(state->out->size() >= state->image_buffer_used); |
- |
- // update the used byte based on the next byte libjpeg would write to |
- state->image_buffer_used = cinfo->dest->next_output_byte - &(*state->out)[0]; |
- DCHECK(state->image_buffer_used < state->out->size()) << |
- "JPEG library busted, got a bad image buffer size"; |
- |
- // update our buffer so that it exactly encompases the desired data |
- state->out->resize(state->image_buffer_used); |
-} |
- |
-// Converts RGBA to RGB (removing the alpha values) to prepare to send data to |
-// libjpeg. This converts one row of data in rgba with the given width in |
-// pixels the the given rgb destination buffer (which should have enough space |
-// reserved for the final data). |
-void StripAlpha(const unsigned char* rgba, int pixel_width, unsigned char* rgb) |
-{ |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &rgba[x * 4]; |
- unsigned char* pixel_out = &rgb[x * 3]; |
- pixel_out[0] = pixel_in[0]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[2]; |
- } |
-} |
- |
-// Converts BGRA to RGB by reordering the color components and dropping the |
-// alpha. This converts one row of data in rgba with the given width in |
-// pixels the the given rgb destination buffer (which should have enough space |
-// reserved for the final data). |
-void BGRAtoRGB(const unsigned char* bgra, int pixel_width, unsigned char* rgb) |
-{ |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &bgra[x * 4]; |
- unsigned char* pixel_out = &rgb[x * 3]; |
- pixel_out[0] = pixel_in[2]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[0]; |
- } |
-} |
- |
-// This class destroys the given jpeg_compress object when it goes out of |
-// scope. It simplifies the error handling in Encode (and even applies to the |
-// success case). |
-class CompressDestroyer { |
- public: |
- CompressDestroyer() : cinfo_(NULL) { |
- } |
- ~CompressDestroyer() { |
- DestroyManagedObject(); |
- } |
- void SetManagedObject(jpeg_compress_struct* ci) { |
- DestroyManagedObject(); |
- cinfo_ = ci; |
- } |
- void DestroyManagedObject() { |
- if (cinfo_) { |
- jpeg_destroy_compress(cinfo_); |
- cinfo_ = NULL; |
- } |
- } |
- private: |
- jpeg_compress_struct* cinfo_; |
-}; |
- |
-} // namespace |
- |
-bool JPEGCodec::Encode(const unsigned char* input, ColorFormat format, |
- int w, int h, int row_byte_width, |
- int quality, std::vector<unsigned char>* output) { |
- jpeg_compress_struct cinfo; |
- CompressDestroyer destroyer; |
- destroyer.SetManagedObject(&cinfo); |
- output->clear(); |
- |
- // We set up the normal JPEG error routines, then override error_exit. |
- // This must be done before the call to create_compress. |
- CoderErrorMgr errmgr; |
- cinfo.err = jpeg_std_error(&errmgr.pub); |
- errmgr.pub.error_exit = ErrorExit; |
- // Establish the setjmp return context for ErrorExit to use. |
- if (setjmp(errmgr.setjmp_buffer)) { |
- // If we get here, the JPEG code has signaled an error. |
- // MSDN notes: "if you intend your code to be portable, do not rely on |
- // correct destruction of frame-based objects when executing a nonlocal |
- // goto using a call to longjmp." So we delete the CompressDestroyer's |
- // object manually instead. |
- destroyer.DestroyManagedObject(); |
- return false; |
- } |
- |
- // The destroyer will destroy() cinfo on exit. |
- jpeg_create_compress(&cinfo); |
- |
- cinfo.image_width = w; |
- cinfo.image_height = h; |
- cinfo.input_components = 3; |
- cinfo.in_color_space = JCS_RGB; |
- cinfo.data_precision = 8; |
- |
- jpeg_set_defaults(&cinfo); |
- jpeg_set_quality(&cinfo, quality, 1); // quality here is 0-100 |
- |
- // set up the destination manager |
- jpeg_destination_mgr destmgr; |
- destmgr.init_destination = InitDestination; |
- destmgr.empty_output_buffer = EmptyOutputBuffer; |
- destmgr.term_destination = TermDestination; |
- cinfo.dest = &destmgr; |
- |
- JpegEncoderState state(output); |
- cinfo.client_data = &state; |
- |
- jpeg_start_compress(&cinfo, 1); |
- |
- // feed it the rows, doing necessary conversions for the color format |
- if (format == FORMAT_RGB) { |
- // no conversion necessary |
- while (cinfo.next_scanline < cinfo.image_height) { |
- const unsigned char* row = &input[cinfo.next_scanline * row_byte_width]; |
- jpeg_write_scanlines(&cinfo, const_cast<unsigned char**>(&row), 1); |
- } |
- } else { |
- // get the correct format converter |
- void (*converter)(const unsigned char* in, int w, unsigned char* rgb); |
- if (format == FORMAT_RGBA || |
- (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { |
- converter = StripAlpha; |
- } else if (format == FORMAT_BGRA || |
- (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { |
- converter = BGRAtoRGB; |
- } else { |
- NOTREACHED() << "Invalid pixel format"; |
- return false; |
- } |
- |
- // output row after converting |
- unsigned char* row = new unsigned char[w * 3]; |
- |
- while (cinfo.next_scanline < cinfo.image_height) { |
- converter(&input[cinfo.next_scanline * row_byte_width], w, row); |
- jpeg_write_scanlines(&cinfo, &row, 1); |
- } |
- delete[] row; |
- } |
- |
- jpeg_finish_compress(&cinfo); |
- return true; |
-} |
- |
-// Decoder -------------------------------------------------------------------- |
- |
-namespace { |
- |
-struct JpegDecoderState { |
- JpegDecoderState(const unsigned char* in, size_t len) |
- : input_buffer(in), input_buffer_length(len) { |
- } |
- |
- const unsigned char* input_buffer; |
- size_t input_buffer_length; |
-}; |
- |
-// Callback to initialize the source. |
-// |
-// From the JPEG library: |
-// "Initialize source. This is called by jpeg_read_header() before any data is |
-// actually read. May leave bytes_in_buffer set to 0 (in which case a |
-// fill_input_buffer() call will occur immediately)." |
-void InitSource(j_decompress_ptr cinfo) { |
- JpegDecoderState* state = static_cast<JpegDecoderState*>(cinfo->client_data); |
- cinfo->src->next_input_byte = state->input_buffer; |
- cinfo->src->bytes_in_buffer = state->input_buffer_length; |
-} |
- |
-// Callback to fill the buffer. Since our buffer already contains all the data, |
-// we should never need to provide more data. If libjpeg thinks it needs more |
-// data, our input is probably corrupt. |
-// |
-// From the JPEG library: |
-// "This is called whenever bytes_in_buffer has reached zero and more data is |
-// wanted. In typical applications, it should read fresh data into the buffer |
-// (ignoring the current state of next_input_byte and bytes_in_buffer), reset |
-// the pointer & count to the start of the buffer, and return TRUE indicating |
-// that the buffer has been reloaded. It is not necessary to fill the buffer |
-// entirely, only to obtain at least one more byte. bytes_in_buffer MUST be |
-// set to a positive value if TRUE is returned. A FALSE return should only |
-// be used when I/O suspension is desired." |
-boolean FillInputBuffer(j_decompress_ptr cinfo) { |
- return false; |
-} |
- |
-// Skip data in the buffer. Since we have all the data at once, this operation |
-// is easy. It is not clear if this ever gets called because the JPEG library |
-// should be able to do the skip itself (it has all the data). |
-// |
-// From the JPEG library: |
-// "Skip num_bytes worth of data. The buffer pointer and count should be |
-// advanced over num_bytes input bytes, refilling the buffer as needed. This |
-// is used to skip over a potentially large amount of uninteresting data |
-// (such as an APPn marker). In some applications it may be possible to |
-// optimize away the reading of the skipped data, but it's not clear that |
-// being smart is worth much trouble; large skips are uncommon. |
-// bytes_in_buffer may be zero on return. A zero or negative skip count |
-// should be treated as a no-op." |
-void SkipInputData(j_decompress_ptr cinfo, long num_bytes) { |
- if (num_bytes > static_cast<long>(cinfo->src->bytes_in_buffer)) { |
- // Since all our data should be in the buffer, trying to skip beyond it |
- // means that there is some kind of error or corrupt input data. A 0 for |
- // bytes left means it will call FillInputBuffer which will then fail. |
- cinfo->src->next_input_byte += cinfo->src->bytes_in_buffer; |
- cinfo->src->bytes_in_buffer = 0; |
- } else if (num_bytes > 0) { |
- cinfo->src->bytes_in_buffer -= static_cast<size_t>(num_bytes); |
- cinfo->src->next_input_byte += num_bytes; |
- } |
-} |
- |
-// Our source doesn't need any cleanup, so this is a NOP. |
-// |
-// From the JPEG library: |
-// "Terminate source --- called by jpeg_finish_decompress() after all data has |
-// been read to clean up JPEG source manager. NOT called by jpeg_abort() or |
-// jpeg_destroy()." |
-void TermSource(j_decompress_ptr cinfo) { |
-} |
- |
-// Converts one row of rgb data to rgba data by adding a fully-opaque alpha |
-// value. |
-void AddAlpha(const unsigned char* rgb, int pixel_width, unsigned char* rgba) { |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &rgb[x * 3]; |
- unsigned char* pixel_out = &rgba[x * 4]; |
- pixel_out[0] = pixel_in[0]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[2]; |
- pixel_out[3] = 0xff; |
- } |
-} |
- |
-// Converts one row of RGB data to BGRA by reordering the color components and |
-// adding alpha values of 0xff. |
-void RGBtoBGRA(const unsigned char* bgra, int pixel_width, unsigned char* rgb) |
-{ |
- for (int x = 0; x < pixel_width; x++) { |
- const unsigned char* pixel_in = &bgra[x * 3]; |
- unsigned char* pixel_out = &rgb[x * 4]; |
- pixel_out[0] = pixel_in[2]; |
- pixel_out[1] = pixel_in[1]; |
- pixel_out[2] = pixel_in[0]; |
- pixel_out[3] = 0xff; |
- } |
-} |
- |
-// This class destroys the given jpeg_decompress object when it goes out of |
-// scope. It simplifies the error handling in Decode (and even applies to the |
-// success case). |
-class DecompressDestroyer { |
- public: |
- DecompressDestroyer() : cinfo_(NULL) { |
- } |
- ~DecompressDestroyer() { |
- DestroyManagedObject(); |
- } |
- void SetManagedObject(jpeg_decompress_struct* ci) { |
- DestroyManagedObject(); |
- cinfo_ = ci; |
- } |
- void DestroyManagedObject() { |
- if (cinfo_) { |
- jpeg_destroy_decompress(cinfo_); |
- cinfo_ = NULL; |
- } |
- } |
- private: |
- jpeg_decompress_struct* cinfo_; |
-}; |
- |
-} // namespace |
- |
-bool JPEGCodec::Decode(const unsigned char* input, size_t input_size, |
- ColorFormat format, std::vector<unsigned char>* output, |
- int* w, int* h) { |
- jpeg_decompress_struct cinfo; |
- DecompressDestroyer destroyer; |
- destroyer.SetManagedObject(&cinfo); |
- output->clear(); |
- |
- // We set up the normal JPEG error routines, then override error_exit. |
- // This must be done before the call to create_decompress. |
- CoderErrorMgr errmgr; |
- cinfo.err = jpeg_std_error(&errmgr.pub); |
- errmgr.pub.error_exit = ErrorExit; |
- // Establish the setjmp return context for ErrorExit to use. |
- if (setjmp(errmgr.setjmp_buffer)) { |
- // If we get here, the JPEG code has signaled an error. |
- // See note in JPEGCodec::Encode() for why we need to destroy the cinfo |
- // manually here. |
- destroyer.DestroyManagedObject(); |
- return false; |
- } |
- |
- // The destroyer will destroy() cinfo on exit. We don't want to set the |
- // destroyer's object until cinfo is initialized. |
- jpeg_create_decompress(&cinfo); |
- |
- // set up the source manager |
- jpeg_source_mgr srcmgr; |
- srcmgr.init_source = InitSource; |
- srcmgr.fill_input_buffer = FillInputBuffer; |
- srcmgr.skip_input_data = SkipInputData; |
- srcmgr.resync_to_restart = jpeg_resync_to_restart; // use default routine |
- srcmgr.term_source = TermSource; |
- cinfo.src = &srcmgr; |
- |
- JpegDecoderState state(input, input_size); |
- cinfo.client_data = &state; |
- |
- // fill the file metadata into our buffer |
- if (jpeg_read_header(&cinfo, true) != JPEG_HEADER_OK) |
- return false; |
- |
- // we want to always get RGB data out |
- switch (cinfo.jpeg_color_space) { |
- case JCS_GRAYSCALE: |
- case JCS_RGB: |
- case JCS_YCbCr: |
- cinfo.out_color_space = JCS_RGB; |
- break; |
- case JCS_CMYK: |
- case JCS_YCCK: |
- default: |
- // Mozilla errors out on these color spaces, so I presume that the jpeg |
- // library can't do automatic color space conversion for them. We don't |
- // care about these anyway. |
- return false; |
- } |
- cinfo.output_components = 3; |
- |
- jpeg_calc_output_dimensions(&cinfo); |
- *w = cinfo.output_width; |
- *h = cinfo.output_height; |
- |
- jpeg_start_decompress(&cinfo); |
- |
- // FIXME(brettw) we may want to allow the capability for callers to request |
- // how to align row lengths as we do for the compressor. |
- int row_read_stride = cinfo.output_width * cinfo.output_components; |
- |
- if (format == FORMAT_RGB) { |
- // easy case, row needs no conversion |
- int row_write_stride = row_read_stride; |
- output->resize(row_write_stride * cinfo.output_height); |
- |
- for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { |
- unsigned char* rowptr = &(*output)[row * row_write_stride]; |
- if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) |
- return false; |
- } |
- } else { |
- // Rows need conversion to output format: read into a temporary buffer and |
- // expand to the final one. Performance: we could avoid the extra |
- // allocation by doing the expansion in-place. |
- int row_write_stride; |
- void (*converter)(const unsigned char* rgb, int w, unsigned char* out); |
- if (format == FORMAT_RGBA || |
- (format == FORMAT_SkBitmap && SK_R32_SHIFT == 0)) { |
- row_write_stride = cinfo.output_width * 4; |
- converter = AddAlpha; |
- } else if (format == FORMAT_BGRA || |
- (format == FORMAT_SkBitmap && SK_B32_SHIFT == 0)) { |
- row_write_stride = cinfo.output_width * 4; |
- converter = RGBtoBGRA; |
- } else { |
- NOTREACHED() << "Invalid pixel format"; |
- jpeg_destroy_decompress(&cinfo); |
- return false; |
- } |
- |
- output->resize(row_write_stride * cinfo.output_height); |
- |
- scoped_array<unsigned char> row_data(new unsigned char[row_read_stride]); |
- unsigned char* rowptr = row_data.get(); |
- for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) { |
- if (!jpeg_read_scanlines(&cinfo, &rowptr, 1)) |
- return false; |
- converter(rowptr, *w, &(*output)[row * row_write_stride]); |
- } |
- } |
- |
- jpeg_finish_decompress(&cinfo); |
- jpeg_destroy_decompress(&cinfo); |
- return true; |
-} |
- |
-// static |
-SkBitmap* JPEGCodec::Decode(const unsigned char* input, size_t input_size) { |
- int w, h; |
- std::vector<unsigned char> data_vector; |
- if (!Decode(input, input_size, FORMAT_SkBitmap, &data_vector, &w, &h)) |
- return NULL; |
- |
- // Skia only handles 32 bit images. |
- int data_length = w * h * 4; |
- |
- SkBitmap* bitmap = new SkBitmap(); |
- bitmap->setConfig(SkBitmap::kARGB_8888_Config, w, h); |
- bitmap->allocPixels(); |
- memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length); |
- |
- return bitmap; |
-} |
- |
-} // namespace gfx |